The current issue of the IETE Journal of Research (Vol.64, No.2, March–April 2018) contains 11 articles. These articles present on-going research and developments taking place in the broad areas of Communication Engineering, Power Systems, Electromagnetics, and Microelectronics.
The paper on “A cognitive viewpoint on building detection from remotely sensed multispectral images,” presents a method to detect buildings from very high resolution multispectral images from satellites. The method uses cognitive approach as used by humans in the framework of cognitive task analysis. The method is studied on test images and the performance of the method is given using different statistical measures.
In “Convolutional neural network training incorporating rotation-based generated patterns and handwritten numeral recognition of major Indian scripts,” the task of recognizing Bangla and Devnagiri handwritten numerals is studied using convolutional neural networks. Both the language scripts have similar shaped numerals. Different training sets corresponding to rotated patterns of the numerals are used to train the CNN. The performance is compared with other methods using benchmark handwritten numeral datasets, and the results are presented.
The next paper titled “Delay-dependent finite-time stabilization of uncertain switched time-delay systems with norm-bounded disturbance,” presents the study of finite-time stabilization for switched time-delay systems that exhibit time-varying uncertainties and norm-bounded disturbance. Such systems are used to model communication networks, power electronics systems etc. The paper gives a method to model the time-varying uncertainties and a state-feedback controller with gain linearization is given for finite-time stabilization of closed-loop system. The effectiveness of the method is illustrated with a numerical example.
In the paper “Design and implementation of a feedback linearization controlled IM drive via simplified neuro-fuzzy approach,” a single-input neuro-fuzzy controller (NFC) is presented that uses decoupling-controlled intuitive feedback linearization for induction motor modelling. A reduced membership function is given. The NFC has the features of reduced torque and speed ripple and also gives improved performance. The performance is studied in simulations and experimental implementation using DSP, and compared with conventional PI-controller and conventional NFC and inferences are drawn.
The paper on “Distributed wind energy conversion system interface to the grid using cascaded multi-level converter,” presents a distributed wind energy conversion system using a cascaded H-bridge multi-level converter topology for medium-voltage grid interfaces. A method for generating references for voltage source converter in current control mode is presented. The advantages of a modular structure of wind turbine-alternator sets and cascaded multi-level inverter using H-bridges is explained. The system is verified using simulation studies with power system transient analysis tool.
In the next paper on “Efficient blind beamforming algorithms for phased array and MIMO radar,” two algorithms for adaptive blind beamforming are presented for communication applications. The algorithms’ convergence rate and side-lobe levels are studied using simulations and are compared with existing algorithms.
The following paper titled “Harmonic level minimization using neuro-fuzzy-based SVPWM” gives the design of a controlling structure to reduce the noise level in the output voltage of a distributed energy source. The combination of two different renewable energy sources is done with a controlling architecture that switches between devices under dynamic load conditions. The control signals are generated using neuro fuzzy structure that is used for generation of regulated power supply. The generation of switching pulse is studied with space-vector pulse width modulation (SVPWM), and is compared with existing method for efficacy.
The paper on “Novel quadrature voltage-controlled oscillator using capacitor coupling,” presents the design of a quadrature voltage-controlled oscillator (QVCO) that is coupled with four capacitors. It is compared with the conventional transformer and MOS transistor coupling in terms of phase noise and power dissipation. The design is verified in simulation environment for the band of 2.05 to 5.25 GHz.
In the paper “On-chip meander line N-well resistor with shielded ground conductor for Q-factor improvement,” a design for on-chip meander line N-well resistor with shielded ground conductor is studied for its efficacy in reducing the parasitic mutual capacitance and thereby improving the Q-factor compared to the case without shielded ground conductor at high frequency. The improvements at 8-10 GHz is reported.
The paper on “Review of feature extraction techniques for character recognition,” reviews the techniques for feature extraction for character recognition. The various independent techniques of feature extraction are discussed. These include statistical features, geometrical features, moment-based features, local features, and spatial relational features. Their efficacy in terms of accuracy of classification as reported in several papers is presented in a consolidated manner.
The paper on “Transmission gate as buffer for carbon-nanotube based VLSI interconnects,” gives the design of transmission gates for use as buffers and repeaters for carbon nanotube based VLSI interconnects. The transmission gate design is studied in terms of several performance metrics such as propagation delay, crosstalk-induced delay, power dissipation, and power-delay product. The performance is compared with CMOS inverter buffers for suitability in carbon nanotube based ICs.
Additional information
Notes on contributors
Shiban K Koul
Shiban K Koul is Dr. R.P.Shenoy Astra Microwave Chair Professor at the Indian Institute of Technology, Delhi. He served as Deputy Director (Strategy and Planning) at IIT Delhi from 2012-2016. Currently, he is the Mentor Deputy Director (Strategy & Planning, International affairs and R&D) at IIT Jammu. He is also the Chairman of Astra Microwave Products Limited, Hyderabad. His research interests include: RF MEMS, High Frequency Wireless Communication, Microwave Engineering, Microwave Passive and Active Circuits, Device modeling, Millimeter wave IC design and Reconfigurable microwave circuits including antennas. Completed 34 major sponsored projects, 52 consultancy projects and 54 Technology Development Projects. Authored 355 Papers, 8 state-of-the art books and 3 book Chapters. He holds 10 patents and 6 copyrights. He is a Fellow of IEEE, INAE, IETE, MANCEF and ISSS. He is the Chief Editor of IETE Journal of Research, Associate Editor of the International Journal of Microwave and Wireless Technologies, Cambridge University Press. He served as a Distinguished Microwave Lecturer of IEEE MTT-S for the period 2012-2014.
Recipient of numerous awards including IEEE MTT Society Distinguished Educator Award (2014); Teaching Excellence Award (2012) from IIT Delhi; Award for contributions made to the growth of smart material technology (2012) by the ISSS, Bangalore, Vasvik Award (2012) for the contributions made to the area of Information, Communication Technology (ICT) and M N Saha Memorial Award (2013) from IETE.
E-mail: [email protected]